Fluid pressure indicator for pneumatic tires and other inflated bodies



gep'im 2Q, 1932. w TURNER 1,878,917-

( FLUID PRESSURE INDICATOR FOR PNEUMATIC TIRES AND OTHER INFLATED BODIES Filed Jan. 5, 1930 INVENTQW William Turner,

ATTORNEX Patented Sept. 20, 1932 WILLIAM TURNER, OF SHEFFIELD, ENGLAND PATET -Fics FLUID PRESSURE INDICATOR Ton PNEUMATIC TIRES AND OTHER InFLAT i) BoiaiEs' Application filed January 3,1930, Serial No. 418,37?, ank1 in Great Britain May 1929,

This invention relates tofluid pressure indicators or gauges for use upon pneumatic tires or other inflated bodies of the kind which is applied directly to the valve tube of the inflated body after removal of the cap so as to place the pressure chamber of the gauge into communication with the interior ofthe inflated body, and in which the pressure indicating member is formed separately at from the pressure-actuated member and is adapted. to be moved outwardly thereby to give an indication of the pressure, and to be retained in its indicating position when the gauge is removed and the is member is retracted.

In the improved construction of such apparatus constituting the present invention, the vpressure cylinder of the gauge has an enlarged head or cap recessed atone side to receive a luting ring or washer of india rubber or equivalent material which, when pressed directly upon the end of the valve tube of the tire or the like, forms an air-tight joint between the gauge cylinder and the tire valve, and into the wall of-the enlarged head is screwed a pin which passes through a central aperture in the recess, leaving a small clearance for the passage of air from the tire to the gauge, this pin serving to engagethe valve pin of the tire valve and force the valve ofi' its seat, and also as an anchor for one end of a coiled tension spring the other end of which is attached to the piston or pressure member'of the gauge.

This piston is fitted with a cup leather or equivalent packing to make an air-tight sliding fit with the pressure cylinder of the gauge, and its stem has a screw thread 2" formed on it upon which the end of the coiled spring is screwed to a greater or less extent, as may be required for adjustment purposes.

The invention is illustrated in the accompanying drawing in which Fi 1 is a longitudinal section and Fig. 2 a transverse section on line 2-2 in Fig. 1.

The pressure cylinder at of the gauge has an enlarged cap or' head I) screwed into one end, a packing ring 0 being interposed to form an air-tight joint. The wall at one pressure-actuated side of the head has a recess d to receive an.

india rubber lilting-ringorwashere, and this recess has a central aperturef through which a pin 9 passes and is screwed into the opposite wall of the head I). The outerend of this pin 9 is arranged toproject sufiiciently to' engage the valve pinof the usual type of tire valve, and to'displace' the valve from its seating when the rubber washer e is firmly pressed against the end of the tire valve tube. v

The aperture f is slightly larger than the diameter o-fthe pin, so that the area of the air passage left between them is small enough to check any sudden inflow of air from the tire or the like into the gauge, such a. sud

den inflow te The pin 9 also constitutesthe anchor for ding to give inaccurate-react one end of a coiledtension spring h, which is in part accommodated within the hollow cap band the other end of which is attached to the pressure member or pistoni, preferably in an adjustable fashion by screwing the end of the coiled spring-into a thread 2' cut on the stem of the piston 2'. The piston '2' is *made an air-tight lit with the pressure cylinder a, as by means of a cup leather j.

Cooperating with the piston '2' is the indicator stem is which, as shown, is preferably of triang'ular section and has upon each of 'itsseveral faces a graduated scale of pres-- sure-s. The inner end 'ofthe indicator stem is has a cylindrical head Z which, by means of a spring ring m or the equivalent thereof, is friction-tight in the cylinder at, so that when the indicator-stemis pushed outwards it will remain in the position to which it has been expelled when the gauge has been removed from-the tire valve and the piston z is retracted. 1 f

To ensure-that the indicator stem'le will not be retracted by the suction established between its head Z and the piston'z'when the latter isdrawn back by its spring it, an aperture n is providedin the-headl'soas to break the vacuum between the head and the piston The triangular stem is extendsthrough and is guided by atriangular aperture 0 in a cap 0 which is screwed on to the outer end of the pressure cylinder at, and this cap 0 also servesto prevent the-indicatorstem Zr:

claim from being completely pushed out from the pressure cylinder.

To prevent any tendency of the piston 71 to adhere to the cylindrical head Z, the adjacent faces of the piston and the head Z are coned or curved, or one of them is coned or curved so thatthere is substantially a point contact between'the two.

Having thus describe-d the nature of the said invention and the best means I" know of carrying the same info practicalleflect', I

1. A fluid pressure gauge of the character herein described comprising a pressure cylinder, a'hollow cap'on'one end thereof, said cap having a circular aperture in one of its sides, a transverse pin of a. diameter slightly less than the said aperture secured within said cap and extending with small clearance ,member slidably mounted vwithinsaid pressure cylinder, and a coiled spring extending herein described, comprising a pressure .cyl-

into the said hollow cap and connected with said pressure member and said, transverse.

in. y 7 i 2. A fluid pressure gauge of the character herein described cornprisin a pressure cylinder, a hollow cap on one end thereon-said cap having a circular aperture in one of its I sides, a transverse pin of a diameter slights 1y less than the said aperture-secured within said cap and extending with small clearance through said aperture, a nipressure-actuated,

member slidably mounted ,within'said press "sure cylinder and having a screwthread cut thereon, and a coiled spring extending into apertures, a pressure-actuated member slidably mounted within said pressure cylinder, a screwthread out on said pressure-actuated member, a coiled spring having one end screwed on said screwthread and the other end connected with said transverse pin, and a longitudinally movable pressure-indicating member having aportion making friction-tight contact with said pressure cylinder and substantially point contact with said pressure-actuated member, said friction-tight contactsmaking portion being apertured longitudinally, said pressure indicating member having an indicating stem of triangular cross section.

In testimony whereof I have signed m name to this specification. V

i r WILLIAM TURNER. Y

through'said aperture, a pressure-actuated the said hollow cap and having one end I "screwed upon said screwthread and its other end. connected with said transverse pin.

3. A fluid pressure gauge of the character 4. A fluid pressure gauge of the character 7' 7 herein described, comprising a pressure cyl-. V V inder, a cap OIl-OI19wI1d5tl18TBO saidv cap" 7 having a circularapertured recess formed in one of its sides, a luting ring seatedin said recess and having an aperture registering with the aperture in the cap, a transverse pin of a diameter-slightly less than the said aperture secured withinthe cap: and extending with small clearance through said 

